The boost pressure, i.e., the pressure at which combustion air is supplied to an internal combustion engine, has an important influence on the emissions from the internal combustion engine. It is therefore necessary to be able to recognize errors in the boost pressure system, in particular the actuators for the boost pressure system. This includes not only recognition of a complete failure or defect of an actuator, but also recognition of age-related deterioration.
It is known from prior use to monitor allowable system deviations in steady-state operation of the internal combustion engine. However, this type of monitoring does not allow recognition of errors which occur in a non-steady state of the boost pressure system or of the internal combustion engine.